This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A112000 #5 Jul 09 2017 08:41:31 %S A112000 -3,65,-1190,22050,-433125,9144135,-208107900,5099994900, %T A112000 -134219460375,3781060408125,-113633468798850,3631422078033750, %U A112000 -123022987568105625,4405418319999571875,-166312279434175875000,6602853358582065585000,-275059081486584416896875 %N A112000 One half of third column (k=2) of triangle A111999. %F A112000 a(n)=A111999(n+3, 2)/2, n>=0. %F A112000 Conjecture: +n*(4*n+5)*a(n) +(2*n+3)*(n+2)*(4*n+9)*a(n-1)=0. - _R. J. Mathar_, Jul 09 2017 %Y A112000 Cf. Second (k=1) column: A000906(n+2)*(-1)^n = 2*A000457(n+2)*(-1)^n, n>=0. %K A112000 sign,easy %O A112000 0,1 %A A112000 _Wolfdieter Lang_, Sep 12 2005